JPH0787524B2 - Data communication controller - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a data communication control device, and more particularly to a data communication control device applicable to a communication system in which communication cannot be performed beyond a communication time of a predetermined time length.

2. Description of the Related Art There is no ordinary wired or wireless communication system having a limited communication time except for pay public telephones, for example.

As a wireless system, there is a system for effectively using radio waves by setting a restriction on communication time, for example, an MCA (multi-channel access) system. In this method, the communication connection is forcibly disconnected when the communication time of a predetermined length elapses.

However, when facsimile communication is performed by the MCA method, the line connection may be disconnected during the communication, for example, while transmitting a page with a document. Call recovery like this
For whatever reason, it is difficult for the receiving side as well as the transmitting side to make a decision. Therefore, information may not be properly transmitted.

Therefore, there is a demand for a method in which information is reliably and efficiently transmitted even in such a communication system having a limited communication time, and the entire system is efficiently used.

Object In view of such a demand, an object of the present invention is to provide a data communication control device capable of transmitting information reliably and efficiently.

In order to achieve the above object, the present invention provides a data communication control device applicable to a communication system in which communication time is restricted, and timer means for measuring time from the start of communication, and communication within the communication time. Monitoring means for monitoring that the time means for securing the time required to execute the interruption procedure is timed by the timer means, and the remaining amount of data to be transmitted within the time obtained by subtracting the time limit from the communicable time. A detection unit that detects whether or not the amount of communication is possible, and if the timer unit measures the time limit during communication of image data, whether to continue communication based on the detection result of the detection unit. And a determining means for determining the remaining amount of data to be transmitted by the detecting means is an amount that can be communicated within the time obtained by subtracting the time limit from the communicable time. If it is detected that the communication is continued, while the remaining amount of data to be transmitted by the detecting means is detected as the amount that cannot be communicated within the time obtained by subtracting the time limit from the communication available time. Is characterized in that the communication interruption procedure is executed to interrupt the communication.

In this specification, the term "data" is to be interpreted in a broad sense, including not only digital data in a narrow sense, but also analog image information such as facsimile information and voice information. Hereinafter, a specific description will be given based on an embodiment of the present invention.

Referring to FIG. 1, in an embodiment of a data communication control device according to the present invention, a facsimile device 100 is connected to a transceiver 200. In the present embodiment, the transmitter / receiver 200 is a wireless transmitter / receiver according to the MCA communication method in which the use of radio waves is time-limited, and it transmits radio waves in a predetermined band to other stations and receives them from other stations. Is configured. However, the present invention is effectively applied not only to the MCA communication method but also to any wireless or wired communication system with a limited communication time.

The signal line 102 from the transceiver 200 is a modulator / demodulator (MODEM) 104.
And a decoding decoder (CODEC) 108 via a buffer 106
It is connected to the. The buffer 106 is a memory that temporarily stores facsimile data to be transmitted and received facsimile data. The modulator / demodulator 104 is a modulator / demodulator that modulates a facsimile signal to be transmitted by a predetermined modulation method and demodulates a received facsimile signal. The encoding / decoding unit 108 is an encoding / decoding circuit that frames a facsimile signal to be transmitted, compression-encodes it according to a predetermined encoding method, deframes the received facsimile signal, and decodes / reproduces with the encoding method.

The facsimile data to be transmitted is sequentially read by the photoelectric conversion element 324 of the reading unit 116 from the original 300 (FIGS. 3 and 4) by raster scanning, and stored in the line buffer 118 in units of one sub-scanning line. This is the line buffer 118
Are sequentially read out to the encoding / decoding device 108 from the encoding / decoding device 1
It is transferred to the buffer 106 through the changeover switch SW1 of 08.

As shown in FIG. 3, the reading unit 116 has a mechanism in which a document 300 placed on a document tray 302 is separated by a separation roller 322.
Then, the sheets are separated one by one, and are sequentially conveyed by the conveying roller 306 toward the reading position P2. At the reading position P2, a fluorescent tube 308 is arranged below the target glass 312, and the emitted light 326 thereof is reflected by the image information carrying surface of the original 300 to form a mirror.
It is configured to enter the photoelectric conversion element 324 via 310. A document holding plate 318 is provided on the target glass 312 so as to cover it, and the gap between them is set to the document 300.
Is passed and is discharged to the document discharge tray 314 by the discharge roller 316.

The original 300 is conveyed in the direction of arrow A, and the original sensor 304 is arranged immediately before the separation roller 322 in the conveying direction. The document sensor 304 is a photo interrupter type or limit switch type detector, and detects the stack of the documents 300, that is, the presence or absence of a document to be transmitted next. A photo interrupter-type document sensor 320 is also arranged behind the transport roller 306.

As shown in the enlarged view of FIG. 4, the document sensor 320 is arranged in front of the document reading position P2 by a predetermined distance L in the transport direction A, and has a length exceeding the predetermined distance L from the reading position P2. It has a function of detecting whether or not 300 exists.
This detection is performed by identifying whether or not the trailing edge 330 of the document 300 is present at the position of the sensor 320 based on the output of the sensor 320 when a predetermined time has elapsed from the start of communication. When the passage of the trailing edge 330 of the document 300 is detected,
From that point, the system control unit 136, which will be described later, can determine that the message to be transmitted ends if the original 300 is conveyed by the number of sub-scanning lines corresponding to the predetermined distance L at most.

For example, the trailing edge 330 of the document 300 is located at a distance L1 from the reading position P2.
If it is in the position shown in FIG.
It is found that the rear end 330 of 00 is not at the position of the distance L, and it is determined that the transmission message ends before the time for transmitting the message of the number of scanning lines corresponding to the length of the distance L has elapsed.

On the other hand, the received facsimile data is read from the buffer 106 to the encoding / decoding unit 108, and stored in the line buffer 120 through the changeover switch SW2 of the encoding / decoding unit 108 in units of one sub-scanning line. This is the line buffer 120
The data is sequentially read from the recording unit 122 to the recording unit 122 and recorded as a hard copy on the recording medium by the recording unit 122.

The changeover switch SW1 has a transmission side terminal S and a character output terminal C, and the character output terminal C is the same terminal C of the switch SW2.
At the same time, it is finally connected to the image signal conversion unit 124. The receiving side terminal R of the changeover switch SW2 is the switch SW1.
Finally, it is connected to the buffer 106. Switching of the changeover switches SW1 and SW2 is controlled by the system control unit 136.

The image signal conversion unit 124 is connected to the character generation circuit (CG) 126,
This is a circuit for converting the character pattern data generated by the character generation circuit 126 into an image signal. When the character data generated in this device is transmitted from the receiver 200, the output of the image signal conversion unit is transferred to the buffer 106 through the switch SW1, and when the character data generated in this device is output to the recording unit 122, The output of the image signal converter 124 is transferred to the line buffer 120 through the switch SW2. The character generation circuit 126 may be a normal character generator that generates character pattern data according to the character data from the system control unit 136 or the timer circuit 130.

The signal line 102 also includes a procedure signal detector 110 and a procedure signal transmitter 1
12 and the call detection unit 114. The procedure signal detection unit 110 has a function of detecting a procedure signal received by the transceiver 200 from the partner station in a facsimile transmission control procedure such as a G3 facsimile transmission control procedure according to CCITT recommendation. The procedure signal transmission unit 112 is a functional unit that transmits a procedure signal to be transmitted from the transceiver 200 to the partner station to the transceiver 200 under the control of the procedure signal control unit 128 in a facsimile transmission control procedure.

The call detection unit 114, when the device is in the automatic incoming call mode,
It has a function of detecting the ringing signal received by the transceiver 200 from the partner station and notifying the system control unit 136. The call detection unit 114 is connected to the timer circuit 130 via the changeover switch SW3 controlled by the system control unit 136.

As will be described later, the timer circuit 130, when making a call, calls the other station and enters the communication start state when the system control unit 136
Is a counter circuit that is activated by the transmitter / receiver 200 and counts the elapse of the communication time within a predetermined communicable time T (FIG. 2) assigned to the transmitter / receiver 200 for transmitting radio waves. Its output 13
2 is connected to the procedure control unit 128 and the transmission determination unit 150.

The transmission determination unit 150 determines that the original 3 has already been included in the communication time T.
It is detected whether or not the time required for sending the facsimile data of 00, that is, the message, exceeds a predetermined reference value t (FIG. 2), and when it exceeds the reference value t, the sensor 32
This circuit reads the output signal from 0 and determines whether or not to continue message transmission.

More specifically, in a communication system in which the communication time length is limited, the time limit t is subtracted from the finite communication available time T in order to prevent the connection from being forcibly disconnected during the transmission of one unit of message. Within the remaining time ta, it must be judged whether or not the transmission of the one unit message can be completed. In this embodiment, the predetermined reference value t is set to the following value. That is, when the time corresponding to the reference value t has elapsed, the time required to transmit the image information of the original 300 corresponding to the length L and the time required to execute the normal facsimile transmission end procedure x (FIG. 2). The transmission determination unit 150 is set so that the sum is at most substantially equal to the remaining time ta in the available communication time T.

It is determined by the sensor whether or not the image information of the original 300 corresponding to the length L is not transmitted yet by the rear end 330 of the original 300.
Detected by 320. This is input from the reading unit 116 to the transmission determination unit 150. In the transmission determination unit 150, the sensor 320
It is determined from this information from the above and the elapsed time information from the timer circuit 130 whether or not the transmission is further continued.

In the present embodiment, the sensor 320 that defines the document reading position P2 is used to determine the amount of untransmitted information of the document 300.
Other means of determining the amount of untransmitted information in 300 may be utilized.

The functions and operations of these parts inside the device are controlled by the system controller.
Controlled by 136. The system controller 136
In this embodiment, a processing system such as a microprocessor is advantageously used.

A display 138 is connected to the system controller 136. This is for displaying to the user that the connection has been cut off due to lack of remaining communication time while the original 300 to be transmitted remains. This display may be a visual display or an audio audible display.

By the way, in a communication system in which the communication time length is limited, the connection may be forcibly disconnected during the transmission of one unit of message. In the present embodiment, when the above-mentioned predetermined time period t is reached, it is determined whether or not the transmission can be continued until the end of the message being transmitted and the normal termination procedure can be executed. If it is determined that the transmission is possible, the transmission is continued as it is. If the transmission is determined to be impossible because the length of the remaining document is long or the amount of information to be transmitted is large, the transmission is stopped and a predetermined termination procedure is executed.

When the transmission is stopped by the latter, the reason is notified to the partner station as an auxiliary message and the termination procedure is executed. This ancillary message transmission and termination procedure is performed within time ta.

As shown in FIG. 2, for example, in the case of transmitting a long message that exceeds the communicable time T, if the remaining communicable time becomes short, as shown in FIG. If so, the call connection will suddenly be restored,
Not only the receiving station RX but also the transmitting station TX cannot grasp the situation accurately. In order to avoid such a situation, in the present embodiment, the transmitting station TX
Determines whether the message can be transmitted until the end. If possible, continue the transmission and perform the termination procedure. This is completed within the remaining time ta. If it is not possible, the transmission is stopped, and at the remaining time ta, the reason for the transmission stop is sent to the receiving station RX as an auxiliary message, and the receiving station RX records this as visible information such as characters or symbols on the recording paper. To do.

First, when a message takes a time t during transmission, for example, as illustrated in FIG. 2A, when the time t has elapsed, it is determined whether the message can be transmitted until the end. If possible, stop sending the message,
Send an ancillary message with a given remaining time ta. This ancillary message is advantageously used, for example, that "the specified time has passed and the message still remains but cannot be sent in full".

After the transmission of this auxiliary message is completed, a normal termination procedure is performed, that is, a sequence of transmitting an EOP (procedure end) signal, returning an MCF signal, and transmitting a DCN (disconnect command) signal, that is, the process moves to x in FIG. . Therefore, the length of the above-described predetermined time period t is set so that these auxiliary messages are transmitted and the termination procedure is executed within the remaining time ta within the communicable time T.

By the way, when the transceiver 200 uses the MCA wireless communication system, there is a time restriction of using the radio wave, and therefore the radio wave is efficiently used from the viewpoint of the entire system.

Referring to FIG. 2, a call connection flow in which the present apparatus performs typical facsimile transmission of a document of a plurality of pages according to the CCITT recommended G3 facsimile transmission control procedure will be described. In this example, the device functions as the transmitting station TX. RX station
May be the present device or another device.

The system control unit 136 of the transmission station TX first activates the procedure signal control unit 128 in response to an instruction from the operator, and then the procedure signal transmission unit 1
Call the receiving station RX from 12 through the transceiver 200. This calling is performed by sending a calling signal in the automatic mode. In response to the ringing signal, the receiving station RX sends back a CED (Called station identification) signal to the transmitting station TX, followed by DIS.
(Digital identification) signal is returned. In the manual mode, the transmitting station TX calls by a voice signal, and the receiving station RX responds to this by operating the operation button.

The system control unit 136 of the transmitting station TX connects the switch SW3 to the terminal TX side together with the calling of the partner station and connects the timer circuit 130
To start. As a result, counting of the already communicated time is started. The procedure signal detection unit 110 of the transmission station TX detects the CED and DIS signals, and the system control unit 136 responds to this and sends out a DCS (digital command) signal in the same manner as described above. After that, a predetermined modem training pattern signal is transmitted to the receiving station RX according to a normal facsimile transmission control procedure, and training of the modulation / demodulation device of the receiving station RX is performed. When the receiving station RX finishes the training, it returns a CFR (reception preparation confirmation) signal to the transmitting station TX.

When the transmitting station TX detects the CFR signal in the procedure signal detection unit 110, the system control unit 136 causes the encoder / decoder 108 to switch.
Connect SW1 to the S terminal side and control the reading unit 116 to control the original 30
Start reading 0 image information. The image information, that is, the message read from the manuscript 300 by the photoelectric conversion element 324 is
It is compression-encoded via the line buffer 118, the encoder / decoder 108, the buffer 106, and the modulator / demodulator 104, assembled into a transmission frame, modulated, and transmitted from the transceiver 200 as a radio wave.

The receiving station RX receives this message, demodulates it, deframes it, reproduces the code, and finally outputs it as a hard copy 504 from the recording unit to the recording paper 500.

Generally, at the beginning of reception, sender information and date / time information 506 are recorded. For this, for example, the sender display function described in JP-A-54-106110 is advantageously applied. At that time, the system control unit 136 connects the switch SW1 of the encoding / decoding unit 108 to the terminal C side. As for the data of the transmission source, a necessary message is assembled from the system control unit 136 and the timer circuit 130 of the transmission station TX, expanded by the character generation circuit 126 as dot pattern data, and transmitted. At the receiving station RX, this is recorded on the recording paper 500 by the recording unit 122 in the same manner as a normal message.

In this embodiment, the image information message for one unit, that is, one page in this embodiment is transmitted from the transmitting station. When the next transmission original does not exist, the system control unit 136 of the transmission station TX sends an EOP (procedure end) signal in the end processing, and the reception station RX returns an MCF signal in response to this.
When the TX of the transmitting station detects the MCF signal, it returns a DCN (disconnect command) signal to the receiving station RX to restore this connection.

Meanwhile, during that time, the system control unit 136 of the transmitting station TX monitors the count value of the timer circuit 130. When this count value, that is, the already communicated time reaches the above-mentioned predetermined reference value t,
The transmission determination unit 150 determines whether the message can be transmitted until the end. This is performed by taking in the output from the sensor 320 of the reading unit 116 at that time by the transmission determination unit 150 and determining whether or not it indicates the presence of the document 300 at the position P1.

If the remaining message, that is, the portion of the document 300 having a length of L or less can be transmitted, that is, if it is determined that the sensor 320 does not detect the presence of the document 300, the transmission determination unit 150 instructs the system control unit 136. The system control unit 136 continues the transmission until the end of the message being transmitted at that time. That is, the image information is read by the reading unit 116 up to the final end 330 of the document 300 and transmitted. When this is completed, the transmitting station
The TX system control unit 136 uses the normal end process x (second
Figure). That is, the EOP signal is transmitted and the receiving station RX
Responds by sending back an MCF signal. TX of transmitting station is M
When the CF signal is detected, the DCN signal is sent back to the receiving station RX to restore this connection. These are performed within the remaining time ta.

When the remaining message cannot be transmitted, that is, there is a portion of the original 300 having a length L or more, and the sensor 320 causes the original 300
If the transmission determining unit 150 determines that the presence of the above is detected, the transmission determining unit 150 notifies the system control unit 136 of that fact, and the encoding / decoding unit 108
The switches SW1 and SW2 are switched to the terminal C side. The system control unit 136 stops the transmission of the message, sends the above-mentioned auxiliary message by the character generation circuit 126 and the image signal conversion unit 124, and then ends by the procedure signal control unit 128 and the procedure signal sending unit 112. Perform necessary termination processing such as procedures, and finally restore the call connection.

More specifically, the system control unit 136 stops the transmission of the message, the above-mentioned auxiliary message is assembled from the system control unit 136 and the timer circuit 130, expanded by the character generation circuit 126 as dot pattern data, and coded. From the terminal C side of the switch SW1 of the decoding decoder 108 to the buffer 106,
It is transmitted through the modulator / demodulator 104 and the transceiver 200. At the receiving station RX, this is done like a normal message in the recording section.
Record on recording paper at 122. After that, the system control unit 136 of the transmitting station TX performs a normal termination process x.

In this embodiment, when the communication is restored in this way even when there are remaining originals, the system control unit 136 of the transmitting station TX activates the display unit 138 to display that effect.

As described above, the transmitting station TX has the time limit function, and by this, the communication time is monitored to determine whether or not the remaining message can be transmitted within the communicable time. When it is possible, it sends it, and when it is not possible, by notifying the receiving station RX of the time limit, we are trying to improve the service so as not to give the recipient the impression of sudden line disconnection. . Therefore, the reliability of information transmission is improved.

In the illustrated embodiment, the present invention has been described with respect to the standard transmission procedure of the CCITT recommendation G3 facsimile, but the present invention is effectively applied to the facsimile according to other transmission procedures such as the same G2 facsimile and other data transmission. It

Further, in the above-described embodiment, the image information of the original 300 is directly read and transmitted from the reading unit 116, but the present invention is also applicable to a system in which a predetermined unit of message is transmitted from the information held in the memory. Is effectively applied. In that case, the remaining amount of information can be determined by managing the address for reading information from the memory. That is, the remaining information amount is determined by comparing the final address in which the information to be transmitted is stored with the address of the information currently being transmitted. It may be configured to determine whether or not to continue the transmission at the time period t in consideration of the transmission time of the remaining information amount and the time required for the normal termination procedure.

Advantageous Effects According to the present invention, in a data communication method in which the communication time length is restricted, the transmitting station is equipped with a time limit function to monitor the communication time, and the remaining information within the communication time before the communication time elapses. It is determined whether or not the transmission can be completed. When it is possible, it will be sent, and when it is not possible, it will be notified to the receiving station accordingly. In this way, the service is improved so as not to give the recipient the impression of a sudden disconnection.

Therefore, the operability of the device and the reliability of information transmission are improved. Therefore, the uncertainty of information transmission and the inconvenience of the user in the conventional method are eliminated, and for example, facsimile information can be reliably and efficiently transmitted. In particular, the wireless communication system is also effective for effective use of radio waves.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing an embodiment of a data communication control device according to the present invention, and FIG. 2 is a CCITT recommendation G in the embodiment shown in FIG.
3 Flowchart showing an example of a call connection flow for performing typical facsimile transmission of a document of a plurality of pages according to a facsimile transmission control procedure, and FIG. 3 is a structural example of a mechanical portion of a reading unit in the embodiment shown in FIG. FIG. 4 is an explanatory view showing a part of FIG. 3 in an enlarged manner. Description of main part code 112 …… Procedure signal sending unit 116 …… Reading unit 126 …… Character generation circuit 128 …… Procedure signal control unit 130 …… Timer circuit 136 …… System control unit 138 …… Display unit 150 …… Transmission judgment section 304, 320 ... Original sensor

Claims (1)

[Claims] 1. A data communication control device applicable to a communication system having a limited communication time, a timer means for measuring a time from the start of communication, and a communication interruption procedure for executing the communication interruption procedure within the communication time. A monitoring unit that monitors that a time period that secures the required time is clocked by the timer unit, and whether the remaining amount of data to be transmitted is an amount that can be communicated within the time obtained by subtracting the time period from the communicable time. And a determination means for determining whether or not to continue the communication based on the detection result of the detection means when the timer means measures the time limit during the communication of image data. When the detection means detects that the remaining amount of data to be transmitted is an amount that can be communicated within the time obtained by subtracting the time limit from the communication possible time, the communication means performs the communication. On the other hand, while continuing, when the remaining amount of data to be transmitted is detected to be the amount that cannot be communicated within the time obtained by subtracting the time limit from the communicable time, the communication interruption procedure is executed. A data communication control device, characterized in that the data communication control device is interrupted.